content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable.internal.operators;
  
  import static org.junit.Assert.*;
  import static org.mockito.ArgumentMatchers.*;
  import static org.mockito.Mockito.*;
  
  import java.util.*;
  import java.util.concurrent.*;
  import java.util.concurrent.atomic.*;
  
  import org.junit.Test;
  import org.mockito.InOrder;
  
  import io.reactivex.common.*;
  import io.reactivex.common.annotations.Nullable;
  import io.reactivex.common.exceptions.TestException;
  import io.reactivex.common.functions.*;
  import io.reactivex.common.internal.schedulers.ImmediateThinScheduler;
  import io.reactivex.observable.*;
  import io.reactivex.observable.Observable;
  import io.reactivex.observable.Observer;
  import io.reactivex.observable.extensions.*;
  import io.reactivex.observable.internal.operators.ObservableObserveOn.ObserveOnObserver;
  import io.reactivex.observable.observers.*;
  import io.reactivex.observable.subjects.*;
  
  public class ObservableObserveOnTest {
  
      /**
       * This is testing a no-op path since it uses Schedulers.immediate() which will not do scheduling.
       */
      @Test
      public void testObserveOn() {
          Observer<Integer> observer = TestHelper.mockObserver();
          Observable.just(1, 2, 3).observeOn(ImmediateThinScheduler.INSTANCE).subscribe(observer);
  
          verify(observer, times(1)).onNext(1);
          verify(observer, times(1)).onNext(2);
          verify(observer, times(1)).onNext(3);
          verify(observer, times(1)).onComplete();
      }
  
      @Test
      public void testOrdering() throws InterruptedException {
  //        Observable<String> obs = Observable.just("one", null, "two", "three", "four");
          // FIXME null values not allowed
          Observable<String> obs = Observable.just("one", "null", "two", "three", "four");
  
          Observer<String> observer = TestHelper.mockObserver();
  
          InOrder inOrder = inOrder(observer);
          TestObserver<String> ts = new TestObserver<String>(observer);
  
          obs.observeOn(Schedulers.computation()).subscribe(ts);
  
          ts.awaitTerminalEvent(1000, TimeUnit.MILLISECONDS);
          if (ts.errors().size() > 0) {
              for (Throwable t : ts.errors()) {
                  t.printStackTrace();
              }
              fail("failed with exception");
          }
  
          inOrder.verify(observer, times(1)).onNext("one");
          inOrder.verify(observer, times(1)).onNext("null");
          inOrder.verify(observer, times(1)).onNext("two");
          inOrder.verify(observer, times(1)).onNext("three");
          inOrder.verify(observer, times(1)).onNext("four");
          inOrder.verify(observer, times(1)).onComplete();
          inOrder.verifyNoMoreInteractions();
      }
  
      @Test
      public void testThreadName() throws InterruptedException {
          System.out.println("Main Thread: " + Thread.currentThread().getName());
          // FIXME null values not allowed
  //        Observable<String> obs = Observable.just("one", null, "two", "three", "four");
          Observable<String> obs = Observable.just("one", "null", "two", "three", "four");
  
          Observer<String> observer = TestHelper.mockObserver();
          final String parentThreadName = Thread.currentThread().getName();
  
          final CountDownLatch completedLatch = new CountDownLatch(1);
  
          // assert subscribe is on main thread
          obs = obs.doOnNext(new Consumer<String>() {
  
              @Override
              public void accept(String s) {
                  String threadName = Thread.currentThread().getName();
                  System.out.println("Source ThreadName: " + threadName + "  Expected => " + parentThreadName);
                  assertEquals(parentThreadName, threadName);
              }
  
          });
  
          // assert observe is on new thread
          obs.observeOn(Schedulers.newThread()).doOnNext(new Consumer<String>() {
  
              @Override
              public void accept(String t1) {
                  String threadName = Thread.currentThread().getName();
                  boolean correctThreadName = threadName.startsWith("RxNewThreadScheduler");
                  System.out.println("ObserveOn ThreadName: " + threadName + "  Correct => " + correctThreadName);
                  assertTrue(correctThreadName);
              }
  
          }).doAfterTerminate(new Action() {
  
              @Override
              public void run() {
                  completedLatch.countDown();
  
              }
          }).subscribe(observer);
  
          if (!completedLatch.await(1000, TimeUnit.MILLISECONDS)) {
              fail("timed out waiting");
          }
  
          verify(observer, never()).onError(any(Throwable.class));
          verify(observer, times(5)).onNext(any(String.class));
          verify(observer, times(1)).onComplete();
      }
  
      @Test
      public void observeOnTheSameSchedulerTwice() {
          Scheduler scheduler = ImmediateThinScheduler.INSTANCE;
  
          Observable<Integer> o = Observable.just(1, 2, 3);
          Observable<Integer> o2 = o.observeOn(scheduler);
  
          @SuppressWarnings("unchecked")
          DefaultObserver<Object> observer1 = mock(DefaultObserver.class);
          @SuppressWarnings("unchecked")
          DefaultObserver<Object> observer2 = mock(DefaultObserver.class);
  
          InOrder inOrder1 = inOrder(observer1);
          InOrder inOrder2 = inOrder(observer2);
  
          o2.subscribe(observer1);
          o2.subscribe(observer2);
  
          inOrder1.verify(observer1, times(1)).onNext(1);
          inOrder1.verify(observer1, times(1)).onNext(2);
          inOrder1.verify(observer1, times(1)).onNext(3);
          inOrder1.verify(observer1, times(1)).onComplete();
          verify(observer1, never()).onError(any(Throwable.class));
          inOrder1.verifyNoMoreInteractions();
  
          inOrder2.verify(observer2, times(1)).onNext(1);
          inOrder2.verify(observer2, times(1)).onNext(2);
          inOrder2.verify(observer2, times(1)).onNext(3);
          inOrder2.verify(observer2, times(1)).onComplete();
          verify(observer2, never()).onError(any(Throwable.class));
          inOrder2.verifyNoMoreInteractions();
      }
  
      @Test
      public void observeSameOnMultipleSchedulers() {
          TestScheduler scheduler1 = new TestScheduler();
          TestScheduler scheduler2 = new TestScheduler();
  
          Observable<Integer> o = Observable.just(1, 2, 3);
          Observable<Integer> o1 = o.observeOn(scheduler1);
          Observable<Integer> o2 = o.observeOn(scheduler2);
  
          Observer<Object> observer1 = TestHelper.mockObserver();
          Observer<Object> observer2 = TestHelper.mockObserver();
  
          InOrder inOrder1 = inOrder(observer1);
          InOrder inOrder2 = inOrder(observer2);
  
          o1.subscribe(observer1);
          o2.subscribe(observer2);
  
          scheduler1.advanceTimeBy(1, TimeUnit.SECONDS);
          scheduler2.advanceTimeBy(1, TimeUnit.SECONDS);
  
          inOrder1.verify(observer1, times(1)).onNext(1);
          inOrder1.verify(observer1, times(1)).onNext(2);
          inOrder1.verify(observer1, times(1)).onNext(3);
          inOrder1.verify(observer1, times(1)).onComplete();
          verify(observer1, never()).onError(any(Throwable.class));
          inOrder1.verifyNoMoreInteractions();
  
          inOrder2.verify(observer2, times(1)).onNext(1);
          inOrder2.verify(observer2, times(1)).onNext(2);
          inOrder2.verify(observer2, times(1)).onNext(3);
          inOrder2.verify(observer2, times(1)).onComplete();
          verify(observer2, never()).onError(any(Throwable.class));
          inOrder2.verifyNoMoreInteractions();
      }
  
      /**
       * Confirm that running on a NewThreadScheduler uses the same thread for the entire stream.
       */
      @Test
      public void testObserveOnWithNewThreadScheduler() {
          final AtomicInteger count = new AtomicInteger();
          final int _multiple = 99;
  
          Observable.range(1, 100000).map(new Function<Integer, Integer>() {
  
              @Override
              public Integer apply(Integer t1) {
                  return t1 * _multiple;
              }
  
          }).observeOn(Schedulers.newThread())
          .blockingForEach(new Consumer<Integer>() {
  
              @Override
              public void accept(Integer t1) {
                  assertEquals(count.incrementAndGet() * _multiple, t1.intValue());
                  // FIXME toBlocking methods run on the current thread
                  String name = Thread.currentThread().getName();
                  assertFalse("Wrong thread name: " + name, name.startsWith("Rx"));
              }
  
          });
  
      }
  
      /**
       * Confirm that running on a ThreadPoolScheduler allows multiple threads but is still ordered.
       */
      @Test
      public void testObserveOnWithThreadPoolScheduler() {
          final AtomicInteger count = new AtomicInteger();
          final int _multiple = 99;
  
          Observable.range(1, 100000).map(new Function<Integer, Integer>() {
  
              @Override
              public Integer apply(Integer t1) {
                  return t1 * _multiple;
              }
  
          }).observeOn(Schedulers.computation())
          .blockingForEach(new Consumer<Integer>() {
  
              @Override
              public void accept(Integer t1) {
                  assertEquals(count.incrementAndGet() * _multiple, t1.intValue());
                  // FIXME toBlocking methods run on the caller's thread
                  String name = Thread.currentThread().getName();
                  assertFalse("Wrong thread name: " + name, name.startsWith("Rx"));
              }
  
          });
      }
  
      /**
       * Attempts to confirm that when pauses exist between events, the ScheduledObserver
       * does not lose or reorder any events since the scheduler will not block, but will
       * be re-scheduled when it receives new events after each pause.
       *
       *
       * This is non-deterministic in proving success, but if it ever fails (non-deterministically)
       * it is a sign of potential issues as thread-races and scheduling should not affect output.
       */
      @Test
      public void testObserveOnOrderingConcurrency() {
          final AtomicInteger count = new AtomicInteger();
          final int _multiple = 99;
  
          Observable.range(1, 10000).map(new Function<Integer, Integer>() {
  
              @Override
              public Integer apply(Integer t1) {
                  if (randomIntFrom0to100() > 98) {
                      try {
                          Thread.sleep(2);
                      } catch (InterruptedException e) {
                          e.printStackTrace();
                      }
                  }
                  return t1 * _multiple;
              }
  
          }).observeOn(Schedulers.computation())
          .blockingForEach(new Consumer<Integer>() {
  
              @Override
              public void accept(Integer t1) {
                  assertEquals(count.incrementAndGet() * _multiple, t1.intValue());
  //                assertTrue(name.startsWith("RxComputationThreadPool"));
                  // FIXME toBlocking now runs its methods on the caller thread
                  String name = Thread.currentThread().getName();
                  assertFalse("Wrong thread name: " + name, name.startsWith("Rx"));
              }
  
          });
      }
  
      @Test
      public void testNonBlockingOuterWhileBlockingOnNext() throws InterruptedException {
  
          final CountDownLatch completedLatch = new CountDownLatch(1);
          final CountDownLatch nextLatch = new CountDownLatch(1);
          final AtomicLong completeTime = new AtomicLong();
          // use subscribeOn to make async, observeOn to move
          Observable.range(1, 2).subscribeOn(Schedulers.newThread()).observeOn(Schedulers.newThread()).subscribe(new DefaultObserver<Integer>() {
  
              @Override
              public void onComplete() {
                  System.out.println("onComplete");
                  completeTime.set(System.nanoTime());
                  completedLatch.countDown();
              }
  
              @Override
              public void onError(Throwable e) {
  
              }
  
              @Override
              public void onNext(Integer t) {
                  // don't let this thing finish yet
                  try {
                      if (!nextLatch.await(1000, TimeUnit.MILLISECONDS)) {
                          throw new RuntimeException("it shouldn't have timed out");
                      }
                  } catch (InterruptedException e) {
                      throw new RuntimeException("it shouldn't have failed");
                  }
              }
  
          });
  
          long afterSubscribeTime = System.nanoTime();
          System.out.println("After subscribe: " + completedLatch.getCount());
          assertEquals(1, completedLatch.getCount());
          nextLatch.countDown();
          completedLatch.await(1000, TimeUnit.MILLISECONDS);
          assertTrue(completeTime.get() > afterSubscribeTime);
          System.out.println("onComplete nanos after subscribe: " + (completeTime.get() - afterSubscribeTime));
      }
  
      private static int randomIntFrom0to100() {
          // XORShift instead of Math.random http://javamex.com/tutorials/random_numbers/xorshift.shtml
          long x = System.nanoTime();
          x ^= (x << 21);
          x ^= (x >>> 35);
          x ^= (x << 4);
          return Math.abs((int) x % 100);
      }
  
      @Test
      public void testDelayedErrorDeliveryWhenSafeSubscriberUnsubscribes() {
          TestScheduler testScheduler = new TestScheduler();
  
          Observable<Integer> source = Observable.concat(Observable.<Integer> error(new TestException()), Observable.just(1));
  
          @SuppressWarnings("unchecked")
          DefaultObserver<Integer> o = mock(DefaultObserver.class);
          InOrder inOrder = inOrder(o);
  
          source.observeOn(testScheduler).subscribe(o);
  
          inOrder.verify(o, never()).onError(any(TestException.class));
  
          testScheduler.advanceTimeBy(1, TimeUnit.SECONDS);
  
          inOrder.verify(o).onError(any(TestException.class));
          inOrder.verify(o, never()).onNext(anyInt());
          inOrder.verify(o, never()).onComplete();
      }
  
      @Test
      public void testAfterUnsubscribeCalledThenObserverOnNextNeverCalled() {
          final TestScheduler testScheduler = new TestScheduler();
  
          final Observer<Integer> observer = TestHelper.mockObserver();
          TestObserver<Integer> ts = new TestObserver<Integer>(observer);
  
          Observable.just(1, 2, 3)
                  .observeOn(testScheduler)
                  .subscribe(ts);
  
          ts.dispose();
          testScheduler.advanceTimeBy(1, TimeUnit.SECONDS);
  
          final InOrder inOrder = inOrder(observer);
  
          inOrder.verify(observer, never()).onNext(anyInt());
          inOrder.verify(observer, never()).onError(any(Exception.class));
          inOrder.verify(observer, never()).onComplete();
      }
  
      @Test
      public void testBackpressureWithTakeBefore() {
          final AtomicInteger generated = new AtomicInteger();
          Observable<Integer> o = Observable.fromIterable(new Iterable<Integer>() {
              @Override
              public Iterator<Integer> iterator() {
                  return new Iterator<Integer>() {
  
                      @Override
                      public void remove() {
                      }
  
                      @Override
                      public Integer next() {
                          return generated.getAndIncrement();
                      }
  
                      @Override
                      public boolean hasNext() {
                          return true;
                      }
                  };
              }
          });
  
          TestObserver<Integer> ts = new TestObserver<Integer>();
          o
                  .take(7)
                  .observeOn(Schedulers.newThread())
                  .subscribe(ts);
  
          ts.awaitTerminalEvent();
          ts.assertValues(0, 1, 2, 3, 4, 5, 6);
          assertEquals(7, generated.get());
      }
  
      @Test
      public void testAsyncChild() {
          TestObserver<Integer> ts = new TestObserver<Integer>();
          Observable.range(0, 100000).observeOn(Schedulers.newThread()).observeOn(Schedulers.newThread()).subscribe(ts);
          ts.awaitTerminalEvent();
          ts.assertNoErrors();
      }
  
      @Test
      public void delayError() {
          Observable.range(1, 5).concatWith(Observable.<Integer>error(new TestException()))
          .observeOn(Schedulers.computation(), true)
          .doOnNext(new Consumer<Integer>() {
              @Override
              public void accept(Integer v) throws Exception {
                  if (v == 1) {
                      Thread.sleep(100);
                  }
              }
          })
          .test()
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class, 1, 2, 3, 4, 5);
      }
  
      @Test
      public void trampolineScheduler() {
          Observable.just(1)
          .observeOn(Schedulers.trampoline())
          .test()
          .assertResult(1);
      }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(PublishSubject.create().observeOn(new TestScheduler()));
      }
  
      @Test
      public void doubleOnSubscribe() {
          TestHelper.checkDoubleOnSubscribeObservable(new Function<Observable<Object>, ObservableSource<Object>>() {
              @Override
              public ObservableSource<Object> apply(Observable<Object> o) throws Exception {
                  return o.observeOn(new TestScheduler());
              }
          });
      }
  
      @Test
      public void badSource() {
          List<Throwable> errors = TestCommonHelper.trackPluginErrors();
          try {
              TestScheduler scheduler = new TestScheduler();
              TestObserver<Integer> to = new Observable<Integer>() {
                  @Override
                  protected void subscribeActual(Observer<? super Integer> observer) {
                      observer.onSubscribe(Disposables.empty());
                      observer.onComplete();
                      observer.onNext(1);
                      observer.onError(new TestException());
                      observer.onComplete();
                  }
              }
              .observeOn(scheduler)
              .test();
  
              scheduler.triggerActions();
  
              to.assertResult();
  
              TestCommonHelper.assertUndeliverable(errors, 0, TestException.class);
          } finally {
              RxJavaCommonPlugins.reset();
          }
      }
  
      @Test
      public void inputSyncFused() {
          Observable.range(1, 5)
          .observeOn(Schedulers.single())
          .test()
          .awaitDone(5, TimeUnit.SECONDS)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void inputAsyncFused() {
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          TestObserver<Integer> to = us.observeOn(Schedulers.single()).test();
  
          TestHelper.emit(us, 1, 2, 3, 4, 5);
  
          to
          .awaitDone(5, TimeUnit.SECONDS)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void inputAsyncFusedError() {
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          TestObserver<Integer> to = us.observeOn(Schedulers.single()).test();
  
          us.onError(new TestException());
  
          to
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class);
      }
  
      @Test
      public void inputAsyncFusedErrorDelayed() {
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          TestObserver<Integer> to = us.observeOn(Schedulers.single(), true).test();
  
          us.onError(new TestException());
  
          to
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class);
      }
  
      @Test
      public void outputFused() {
          TestObserver<Integer> to = ObserverFusion.newTest(QueueDisposable.ANY);
  
          Observable.range(1, 5).hide()
          .observeOn(Schedulers.single())
          .subscribe(to);
  
          ObserverFusion.assertFusion(to, QueueDisposable.ASYNC)
          .awaitDone(5, TimeUnit.SECONDS)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void outputFusedReject() {
          TestObserver<Integer> to = ObserverFusion.newTest(QueueDisposable.SYNC);
  
          Observable.range(1, 5).hide()
          .observeOn(Schedulers.single())
          .subscribe(to);
  
          ObserverFusion.assertFusion(to, QueueDisposable.NONE)
          .awaitDone(5, TimeUnit.SECONDS)
          .assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void inputOutputAsyncFusedError() {
          TestObserver<Integer> to = ObserverFusion.newTest(QueueDisposable.ANY);
  
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          us.observeOn(Schedulers.single())
          .subscribe(to);
  
          us.onError(new TestException());
  
          to
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class);
  
          ObserverFusion.assertFusion(to, QueueDisposable.ASYNC)
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class);
      }
  
      @Test
      public void inputOutputAsyncFusedErrorDelayed() {
          TestObserver<Integer> to = ObserverFusion.newTest(QueueDisposable.ANY);
  
          UnicastSubject<Integer> us = UnicastSubject.create();
  
          us.observeOn(Schedulers.single(), true)
          .subscribe(to);
  
          us.onError(new TestException());
  
          to
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class);
  
          ObserverFusion.assertFusion(to, QueueDisposable.ASYNC)
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class);
      }
  
      @Test
      public void outputFusedCancelReentrant() throws Exception {
          final UnicastSubject<Integer> us = UnicastSubject.create();
  
          final CountDownLatch cdl = new CountDownLatch(1);
  
          us.observeOn(Schedulers.single())
          .subscribe(new Observer<Integer>() {
              Disposable d;
              int count;
              @Override
              public void onSubscribe(Disposable d) {
                  this.d = d;
                  ((QueueDisposable<?>)d).requestFusion(QueueDisposable.ANY);
              }
  
              @Override
              public void onNext(Integer value) {
                  if (++count == 1) {
                      us.onNext(2);
                      d.dispose();
                      cdl.countDown();
                  }
              }
  
              @Override
              public void onError(Throwable e) {
  
              }
  
              @Override
              public void onComplete() {
  
              }
          });
  
          us.onNext(1);
  
          cdl.await();
      }
  
      @Test
      public void nonFusedPollThrows() {
          new Observable<Integer>() {
              @Override
              protected void subscribeActual(Observer<? super Integer> observer) {
                  observer.onSubscribe(Disposables.empty());
  
                  @SuppressWarnings("unchecked")
                  ObserveOnObserver<Integer> oo = (ObserveOnObserver<Integer>)observer;
  
                  oo.queue = new SimpleQueue<Integer>() {
  
                      @Override
                      public boolean offer(Integer value) {
                          return false;
                      }
  
                      @Override
                      public boolean offer(Integer v1, Integer v2) {
                          return false;
                      }
  
                      @Nullable
                      @Override
                      public Integer poll() throws Exception {
                          throw new TestException();
                      }
  
                      @Override
                      public boolean isEmpty() {
                          return false;
                      }
  
                      @Override
                      public void clear() {
                      }
                  };
  
                  oo.clear();
  
                  oo.schedule();
              }
          }
          .observeOn(Schedulers.single())
          .test()
          .awaitDone(5, TimeUnit.SECONDS)
          .assertFailure(TestException.class);
      }
  }
  